The Early Devonian (Emsian) acrotretid microbrachiopod Opsiconidion minor Popov, 1981, from the Alaska/Yukon Territory border and Novaya Zemlya

• New records of the poorly known acrotretid (Biernatidae) microbrachiopod Opsiconidion minor Popov are described from middle Emsian strata of the Ogilvie Formation in east­central Alaska and the adjacent Yukon Territory, Canada, and compared with new better­preserved topotypes from the late Early Devonian (Emsian) of Novaya Zemlya, Russia. In Alaska O. minor occurs together with fragmentary material of Lingulipora sp. and an indeterminate discinid. The only other previous record of O. minor, outside the type area, comes from the Early to ?Middle Devonian (Pragian to ?Givetian) of Australia (Victoria and NSW). Opsiconidion Ludvigsen is a stratigraphically extremely long­ranging and cosmopolitan acrotretid, which exhibits a remarkable conservatism; the morphology of the ventral valve remains essentially unchanged from the earliest Ordovician (Darriwilian) records to the Devonian.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Annan geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Other Earth and Related Environmental Sciences (hsv//eng)

Nyckelord

Brachiopoda

Lingulata

Acrotretida

Biernatidae

Devonian

Emsian

Novaya Zemlya

Russia

Alaska

Yukon Territory

Earth Science with specialization in Historical Geology and Palaeontology

Geovetenskap med inriktning mot historisk geologi och paleontologi

Publikations- och innehållstyp

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